A STABILIZER LEG DEVICE

Abstract

 A stabilizer leg device with a stabilizer leg to be moved downwards from an object so as to stabilize the object by bearing through a foot plate (7) on the ground comprises a first engagement member (20) arranged coaxially to a horizontal axis on a part (19) fixed with respect to the object and a shaft (12) having a first end provided with a second engagement member (21) and an opposite second end arranged to be influenced by movement of a second stabilizer leg member with respect to a first stabilizer leg member to make the shaft slide along the stabilizer leg under extension and retraction of the stabilizer leg so as to cause pivoting of the stabilizer leg by a mutual engagement of said engagement members (20, 21). Members (16, 17) guiding the shaft are designed to automatically unlock and lock, respectively, the stabilizer leg with respect to possibility to pivot about said horizontal axis by passing a predetermined position by the second stabilizer leg member upon retraction and extension of the stabilizer leg.

Description

TECHNICAL FIELD OF THE INVENTION AND BACKGROUND ART

[0001] The present invention relates to a stabilizer leg device with a stabilizer leg to be moved downwards from an object, such as a crane vehicle, so as to stabilize this object by bearing through a footplate secured to a lower end of the stabilizer leg onto a support layer on which the object is resting.

[0002] Such a stabilizer leg device is normally a part of a support arrangement fixed to such an object, such as a movable crane construction, by a frame structure to which one or more such stabilizer leg devices are secured for stabilizing the crane construction when this has to carry out work.

[0003] A stabilizer leg device of this type and with the features listed in the preamble of appended claim 1 is known through EP 0 945 318 A1. The use of first and second engagement members for obtaining a movement of the stabilizer leg from a working position of the stabilizer leg device with the footplate bearing on the ground to a parking position in which the footplate points upwards upon a retraction of the second stabilizer leg member with respect to the first stabilizer leg member, means that such a movement may be carried out by pivoting or tilting the stabilizer leg about an horizontal axis. It is then of course essential that the stabilizer leg is in said working position prevented to pivot about said horizontal axis, and in said device known this is obtained by providing a mechanical lock realised by means of a locking pin. This locking pin has to be operated manually making the locking and unlocking actions rather complicated to achieve. Furthermore, such a design has not an optimum reliability, since there is a risk that it is forgotten to carry out the locking action, which may then under extreme conditions result in accidents.

SUMMARY OF THE INVENTION

[0004] The object of the present invention is to provide a stabilizer leg device of the type discussed above being improved in at least some aspect with respect to such stabilizer leg devices already known.

[0005] This object is according to the invention obtained by providing such a stabilizer leg device with the features listed in the characterizing part of appended patent claim 1.

[0006] By providing the arrangement for controlling the movement of the stabilizer leg between the working position and the parking position with guiding members pivoting of the stabilizer leg about said horizontal axis may automatically be prevented by guiding the shaft to slide vertically. Furthermore, by designing these guiding members to interrupt the guiding when the shaft reaches a predetermined position when retracting the stabilizer leg, the stabilizer leg will automatically be allowed to pivot about said horizontal axis for reaching the parking position. This combined with the fact that the second engagement member is positioned on the shaft to enter into engagement with the first engagement member when the second stabilizer leg member is reaching the predetermined position in a stabilizer leg retraction movement and to leave this engagement when reaching the predetermined position in a stabilizer leg extension movement means that the stabilizer leg will automatically be unlocked and locked, respectively, with respect to the possibility to pivot about the horizontal axis by passing the predetermined position by the second stabilizer leg member. Thus, the locking and unlocking of the stabilizer leg will be obtained automatically upon said extension and retraction of the stabilizer leg without involving any manual work and making these actions simple and reliable to obtain.

[0007] According to an embodiment of the invention said first engagement member comprises an at least semi-circular member, such as a disc, fixed to a said part fixed with respect to said object coaxially to said horizontal axis and provided with cogs over at least a part of its circumference, and the shaft is provided with said second engagement member by being at least partially cogged so as to engage with the cogs of the first engagement member. This constitutes a simple and reliable way to accomplish the engagement causing the pivoting action. The cogs of the first engagement member may then according to another embodiment of the invention be provided by a disc in the form of a gearwheel provided with cogs over at least a part of the circumference thereof.

[0008] According to another embodiment of the invention the second end of the shaft is connected to the second stabilizer leg member through a member extending transversally to the extension of the stabilizer leg between this and the shaft resulting in a movement of the shaft with respect to the first stabilizer leg member when the second stabilizer leg member is moved with respect to the first one.

[0009] According to another embodiment of the invention said guiding members are arranged on one hand on a member to be fixedly secured to or being a part of a said object and on the other hand on the shaft.

[0010] According to another embodiment of the invention the guiding members do then comprise first guiding members in the form of wall members providing opposite walls defining a path extending vertically when the object is resting on horizontal ground and the device is in working position and a second guiding member with a width corresponding to the width of said path and to be guided by the walls when moved in the path upon extension and retraction of the stabilizer leg with the second stabilizer leg member being extended beyond said predetermined extension degree, and a first of said wall members has a design configured to co-operate with a design of the second guiding member so as to remove the guiding action upon the shaft by this first wall member when the shaft is in a position obtained by a retraction of said second stabilizer leg member to the position of said predetermined extension degree.

[0011] Said co-operation of the design of the first wall member and that of said second guiding member is then according to another embodiment of the invention configured to allow pivoting of the stabilizer leg and by that the shaft into a position of vertical extension when the object is resting on horizontal ground in an extension movement of the second stabilizer leg member towards said position of predetermined extension degree. The vertical extension of the stabilizer leg to be assumed thereby in the working position is obtained by these features.

[0012] According to another embodiment of the invention the second of said wall members with guiding walls on the opposite side of said path with respect to the guiding walls of the first wall member is designed to form an obstacle to pivoting of the shaft in one direction about an axis in parallel with said horizontal axis when the second stabilizer leg member is in said position of predetermined extension degree. This means that the stabilizer leg may never pivot in the "false" direction and may not pass the position in which it has a vertical extension when pivoting towards this position but be stopped in that position.

[0013] According to another embodiment of the invention the shaft is provided with said first guiding members by having a slot forming said path, the second guiding member is formed by a ridge arranged on said member to be fixedly secured to or being a part of a said object, and said first wall member is designed to by a lower end thereof reach an upper end of said ridge in said position of a predetermined extension degree of the second stabilizer leg member allowing pivoting of the shaft and by that of the second stabilizer leg member in the direction of said second wall member designed to in this position still extend along a part of said ridge for preventing pivoting of the shaft in the opposite direction. This constitutes one possible way of obtaining said path.

[0014] Another way of obtaining said path is according to another embodiment of the invention accomplished by arranging said first guiding members on said member to be fixedly secured to or being a part of the said object and forming the second guiding member by the shaft received between the wall members forming said path. In a further development of this embodiment a portion of the shaft is provided with a recess of a size able to receive said first wall member and by that enable pivoting of the shaft through the first wall member entering the recess on one side of the shaft and exiting the recess on the opposite shaft side.

[0015] According to another embodiment of the invention said power member is a power cylinder with a first stabilizer leg member providing the cylinder chamber thereof and the second stabilizer leg member forming a piston rod of the power cylinder, in which the power member may be a hydraulic cylinder.

[0016] The invention also relates to a support arrangement and a movable crane construction according to the appended claims directed to a support arrangement and a movable crane construction. The advantages of such an arrangement and such a construction appear clearly from the above discussion of the stabilizer leg device according to the present invention.

[0017] Further advantages as well as advantageous features of the invention will appear from the description following below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] With reference to the appended drawings, below follows a specific description of embodiments of the invention cited as examples.

[0019] In the drawings:

Fig 1

is a schematic view of a crane vehicle provided with two stabilizer leg devices according to the invention in an inactive state,

Fig 2

is an enlarged view of a part of the crane vehicle shown in Fig 1 showing one stabilizer leg device in said inactive state more in detail,

Fig 3

is a view of the crane vehicle in Fig 1 with the two stabilizer leg devices in a working position stabilizing the vehicle by bearing through a footplate onto the ground,

Fig 4

is an enlarged view of a part of the crane vehicle shown in Fig 1 showing one stabilizer leg device in a working position more in detail,

Fig 5

is a perspective view of a stabilizer leg device according to an embodiment of the invention in said working position,

Fig 6

is a simplified view of parts of the stabilizer leg device shown in Fig 5 in said working position,

Fig 7

is a view corresponding to Fig 6 for the stabilizer leg retracted from the working position but still having a vertical extension,

Fig 8 and 9

are enlarged views illustrating pivoting of the shaft and by that the stabilizer leg with respect to the crane vehicle by means of engagement members, and

Fig 10

is a view corresponding to Figs 6 and 7 for the stabilizer leg pivoted into said inactive state or parking position obtained after pivoting 180° from the working position shown in Fig 6.

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

[0020] Fig 1 shows schematically an object 1 in the form of a crane vehicle to which a support arrangement 2 is fixed by having a frame structure 3 thereof fixed to the framework of the vehicle. The support arrangement is provided with two stabilizer leg devices 4, 5 according the present invention. Each stabilizer leg device has a stabilizer leg 6 to be moved downwards from the crane vehicle while being extended (prolonged) and tilted by 180° from the parking position shown in Fig 1 so as to stabilize the crane vehicle by bearing through a foot plate 7 secured to a lower end of the stabilizer leg onto the ground on which the vehicle is resting in a working position of the stabilizer leg device as shown in Fig 3. Figs 2 and 4 are enlarged views showing how a stabilizer leg 6 is arranged on the support arrangement 2 in the parking position and in the working position, respectively, of the stabilizer leg device.

[0021] The design and function of a stabilizer leg device according to this embodiment of the invention will now be described while making reference to Figs. 1-10. The stabilizer leg 6 is formed by a power member of the length varying type in the form of a power cylinder with a first stabilizer leg member 8 providing the cylinder chamber thereof and a second stabilizer leg member 9 forming a piston rod of the power cylinder and to an end of which the foot plate 7 is secured. The power cylinder is preferably a hydraulic cylinder. The first stabilizer leg member 8 is by being secured in a holder 10 pivotally connected to the frame structure 3 of the support arrangement 2 about an axis 11 being horizontal when the crane vehicle is resting on horizontal ground. The stabilizer leg 6 may by that be tilted about an axis 11 being perpendicular to the extension of the stabilizer leg.

[0022] A shaft 12 has a second end 13 connected to the second stabilizer leg member 9 through a member 14 extending transversely to the extension of the stabilizer leg 6. The holder 10 is designed to receive and hold a first end 15 of the shaft 12 displaceably in parallel with the longitudinal extension of the stabilizer leg 6 while keeping the shaft 12 in parallel with the stabilizer leg.

[0023] The shaft 12 is a part of an arrangement of the stabilizer leg device configured to control the stabilizer leg to be moved between the parking position shown in Fig 1 and the working position shown in Fig 3. This arrangement does further comprise first guiding members 16, 17 in the form of wall members providing opposite walls defining a path 18 extending vertically when the object is resting on horizontal ground. These first guiding members 16, 17 are arranged on a plate member 19 to be fixedly secured to the frame structure 3 of the support arrangement 2 and by that to the crane vehicle 1. A second guiding member of the arrangement is formed by the shaft 12 itself. The guiding members of the arrangement co-operates so as to obtain the movement of the stabilizer leg between the working position and the parking position as described further below.

[0024] The arrangement further comprises a first engagement member 20 in the form of a gearwheel fixed with respect to the frame structure 3 by being fixed to the plate member 19 and arranged coaxially to the horizontal axis 11. The shaft 12 is provided with a second engagement member by having a cogged part 21. This cogged part 21 is arranged on the shaft 12 to reach and enter into engagement with the cogs of the gearwheel 20 in a predetermined position of the stabilizer leg reached upon retraction of the second stabilizer leg member 9 from the working position shown in Fig 4 and 6 to the position shown in Fig 7. The two first guiding members 16, 17 will guide the shaft to be displaced vertically when moving from the position shown in Fig 6 to that shown in Fig 7. A portion of the shaft is provided with a recess 22 (see especially Fig 8) of a size able to receive a first 16 of the wall members and by that enable pivoting of the shaft through the first wall member entering the recess on side of the shaft and exiting the recess on the opposite shaft side. The recess 22 is located to be aligned with the first wall member 16 in said predetermined position in Fig 7.

[0025] The function of the stabilizer leg device according to the invention will be as follows. When starting from the working position shown in Fig 4-6 the second stabilizer leg member 9 will be retracted into the first stabilizer leg member 8 and the stabilizer leg will through this retraction move to the parking position shown in Fig 2 and Fig 10. When the second stabilizer leg member 9 is retracted to said predetermined position corresponding to Fig 7 the cogged part 21 of the shaft will enter into engagement with the cogs of the gearwheel 20. This engagement will cause further retraction and by that displacement of the shaft to pivot the shaft and this will be enabled by letting the shaft passing over the first wall member 16 thanks to the recess 22. Thus, the shaft 12 will through said retraction move around the gearwheel 20 as shown in Fig 8 and 9 to finally reach the parking position shown in Fig 10 upon retraction of the second stabilizer leg member 9 and by that shortening of the stabilizer leg 6. When instead transferring the stabilizer leg device from the parking position shown in Fig 2 to the working position shown in Fig 4 the power member (stabilizer leg) is controlled to extend the second stabilizer leg member 9 with respect to the first stabilizer leg member 8 causing the cogged part 21 of the shaft to move around the gearwheel 20 while pivoting the stabilizer leg towards said predetermined position shown in Fig 7. Prior to reaching this position the recess 22 of the shaft 12 will move over the first wall member 16 and when reaching said predetermined position being prevented by the second wall member 17 to pivot further. Further extension of the second stabilizer leg member 9 will result in a displacement of the stabilizer leg member 9 in the direction of the extension thereof controlled by the guiding of the shaft 12 in the path 18 provided by the guiding members 16, 17. Accordingly, the stabilizer leg will through the co-operation of the shaft 12 with the guiding members 16, 17 automatically be locked to have a vertical extension when being extending further with respect to said predetermined position shown in Fig 7. Conversely, this locking action will automatically be interrupted when the stabilizer leg reaches said predetermined position shown in Fig 7 upon retraction of the second stabilizer leg member 9 and by that shortening of the stabilizer leg.

[0026] The invention is of course in no way restricted to the embodiment described above, since many possibilities for modifications thereof are likely to be obvious to one skilled in the art without having to deviate from the scope of invention defined in the appended claims.

[0027] The object to be stabilized by a device according to the invention may be any type of object needing such a stabilization to stand safely without moving or any risk to tilt.

[0028] Although not shown, the shaft may provide the first guiding members through a slot therein, in which the second guiding member moving in said path provided by the slot is formed by a ridge being fixed with respect to said object, such as a crane vehicle.

Claims

1. A stabilizer leg device with a stabilizer leg (6) to be moved downwards from an object (1), such as a crane vehicle, so as to stabilise this object by bearing through a footplate (7) secured to a lower end of the stabilizer leg onto a support layer on which the object is resting, said device comprising

• a power member of the length varying type forming the stabilizer leg (6) and configured to have a first stabilizer leg member (8) thereof pivotally connecting an end of the stabilizer leg to said object about an horizontal axis (11) when the object is resting on horizontal ground and a second stabilizer leg member (9) provided with the footplate and extendable and retractable with respect to the first stabilizer leg member in a direction perpendicular to said horizontal axis for length variation of the stabilizer leg, and

• an arrangement configured to control the stabilizer leg (6) to be moved from a working position of the stabilizer leg device with the footplate (7) bearing on the ground to a parking position in which the footplate points upwards upon a retraction of the second stabilizer leg member (9) with respect to the first stabilizer leg member (8) causing a pivoting of this and by that the stabilizer leg (6) about said horizontal axis (11), and from the parking position to the working position upon extension of the second stabilizer leg member (9) with respect to the first stabilizer leg member (8),

said arrangement comprising a first engagement member (20) configured to be arranged coaxially to said horizontal axis (11) on a part (19) fixed with respect to said object and a shaft (12) having a first end provided with a second engagement member (21) and an opposite second end (13) arranged to be influenced by movement of the second stabilizer leg member (9) with respect to the first stabilizer leg member (8) to make the shaft (12) slide along the stabilizer leg (6) under said extension and retraction of the stabilizer leg so as to cause pivoting of the stabilizer leg by engagement of said second engagement member (21) with said first engagement member (20) during extension and retraction of the stabilizer leg,
characterized in that said arrangement comprises guiding members (16, 17) configured to in a said working position of the stabilizer leg device and upon retraction of the stabilizer leg (6) therefrom to a position of predetermined extension degree of said second stabilizer leg member (9) with respect to the first stabilizer leg member (8) prevent pivoting of the stabilizer leg about said horizontal axis (11) by guiding said shaft (12) to slide vertically and upon reaching said predetermined position to interrupt said guiding and allow the stabilizer leg (6) to pivot about said horizontal axis (11), and that said second engagement member (21) is positioned on said shaft to enter into engagement with the first engagement member (20) when the second stabilizer leg member is reaching said predetermined position in a stabilizer leg retraction movement and to leave said engagement when reaching said predetermined position in a stabilizer leg extension movement so as to automatically unlock and lock, respectively, the stabilizer leg (6) with respect to possibility to pivot about said horizontal axis (11) by passing said predetermined position by the second stabilizer leg member (9).

2. A stabilizer leg device according to claim 1, characterized in that said first engagement member (20) comprises an at least semi-circular member, such as a disc, fixed to a said part (19) fixed with respect to said object coaxially to said horizontal axis (11) and provided with cogs over at least a part of its circumference, and that the shaft (12) is provided with said second engagement member (21) by being at least partially cogged so as to engage with the cogs of the first engagement member.

3. A stabilizer leg device according to claim 2, characterized in that the cogs of the first engagement member are provided by a disc in the form of a gearwheel (20) provided with cogs over at least a part of the circumference thereof.

4. A stabilizer leg device according to any of the preceding claims, characterized in that said second end (13) of the shaft (12) is connected to the second stabilizer leg member (9) through a member (14) extending transversely to the extension of the stabilizer leg (6) between this and the shaft (12).

5. A stabilizer leg device according to any of the preceding claims, characterized in that said guiding members (16, 17) are arranged one hand on a member (19) to be fixedly secured to or being a part of a said object and on the other hand on the shaft (12).

6. A stabilizer leg device according to claim 5, characterized in that said guiding members comprise first guiding members (16, 17) in the form of wall members providing opposite walls defining a path (18) extending vertically when the object is resting on horizontal ground and the device is in working position and a second guiding member (12) with a width corresponding to the width of said path and to be guided by the walls when moved in the path upon extension and retraction of the stabilizer leg (6) with the second stabilizer leg member (9) being extended beyond said predetermined extension degree, and that a first (16) of said wall members has a design configured to co-operate with a design of the second guiding member (12) so as to remove the guiding action upon the shaft by this first wall member when the shaft is in a position obtained by a retraction of said second stabilizer leg member to the position of said predetermined extension degree.

7. A stabilizer leg device according to claim 6, characterized in that said co-operation of the design of the first wall member (16) and that of said second guiding member (9) is configured to allow pivoting of the stabilizer leg (6) and by that the shaft (12) into a position of vertical extension when the object is resting on horizontal ground in an extension movement of the second stabilizer leg member (9) towards said position of predetermined extension degree.

8. A stabilizer leg device according to claim 6 or 7, characterized in that a second (17) of said wall members with guiding walls on the opposite side of said path (18) with respect to the guiding walls of the first wall member (16) is designed to form an obstacle to pivoting of the shaft (12) in one direction about an axis in parallel with said horizontal axis (11) when the second stabilizer leg member (9) is in said position of predetermined extension degree.

9. A stabilizer leg device according to any of claims 6-8, characterized in that the shaft (12) is provided with said first guiding members by having a slot forming said path, that the second guiding member is formed by a ridge arranged on said member to be fixedly secured to or being a part of a said object, and that said first wall member is designed to by a lower end thereof reach an upper end of said ridge in said position of a predetermined extension degree of the second stabilizer leg member allowing pivoting of the shaft and by that of the second stabilizer leg member in the direction of said second wall member designed to in this position still extend along a part of said ridge for preventing pivoting of the shaft in the opposite direction.

10. A stabilizer leg device according to any of claims 6-8, characterized in that said first guiding members (16, 17) are arranged on said member (19) to be fixedly secured to or being a part of a said object and the second guiding member is formed by the shaft (12) received between the wall members forming said path (18).

11. A stabilizer leg device according to claim 10, characterized in that a portion of the shaft is provided with a recess (22) of a size able to receive said first wall member (16) and by that enable pivoting of the shaft (12) through the first wall member entering said recess on one side of the shaft and exiting the recess on the opposite shaft side.

12. A stabilizer leg device according to any of the preceding claims, characterized in that said power member is a power cylinder with the first stabilizer leg member (8) providing the cylinder chamber thereof and the second stabilizer leg member (9) forming a piston rod of the power cylinder.

13. A stabilizer leg device according to claim 12, characterized in that the power member is a hydraulic cylinder.

14. A support arrangement configured to be fixed to an object, such as a crane vehicle, so as to give this object (1) support from a support layer on which the object is resting, characterized in that the arrangement (2) comprises a frame structure (3) configured to be fixed to a said object and at least one stabilizer leg device (4, 5) according to any of the preceding claims secured to the frame structure.

15. A movable crane construction, such as a crane vehicle, characterized in that it comprises a support arrangement (2) according to claim 14.

Drawing